Environment control system for aircraft having interior condensation problem reduction, cabin air quality improvement, fire suppression and fire venting functions

Abstract

An environment control system for a body of an aircraft that provides controlled ventilation of the interior space of an aircraft body, facilitating reduction of volatile organic compounds (VOCs) within cabin air, dehumidifying and reducing moisture condensation and thus corrosion and other moisture related problems within the envelope, allowing increased humidification of cabin air, and allowing suppression of fires within the envelope. The environment control system includes at least a cabin and an envelope. It includes supply means for supplying a flow of dry ventilation air to the aircraft body. An airflow control device is capable of dividing the flow of ventilation air onto an envelope ventilation air stream and a cabin ventilation air stream. An envelope ventilation duct system directs the envelope ventilation air stream into the envelope, and a cabin duct system directs the cabin ventilation air stream into the cabin. An anti-corrosion/sorption treatment is applied to surface subject to condensation in the envelope. A return air control unit is provided for selectively drawing return air from one of the envelope and the cabin. The environment control system can be incorporated into new aircraft construction, or can be installed as a retro-fit into existing aircraft.

What is claimed is:  
     
       1. An environment control system installed in the body of an aircraft having a body shell enclosing an inner space, a liner disposed within the inner space and defining an envelope space between the liner and the body shell and an interior space on the other side of the liner, 
       an air supply for providing a flow of dry ventilation air to the inner space of the body,  
       an envelope air distribution system for directing air from the air supply into the envelope space,  
       a return air control unit capable of drawing return air from the interior space, and  
       an air flow controller which controls the flow of air into the envelope space to develop a sufficient pressure in the envelope space relative to the pressure in the interior space to substantially prevent the flow of air from the interior space into the envelope space caused by stack pressure across the liner between the envelope space and the interior space which tends to cause air to flow across the liner from the interior space into the envelope space.  
     
     
       2. An environment control system as claimed in  claim 1 , further comprising means for directing a flow of ventilation air from said air supply into said interior space. 
     
     
       3. An environment control system as claimed in  claim 1 , wherein the envelope air distribution system comprises at least one envelope supply duct disposed longitudinally in the aircraft body and at least one respective ventilation air branch line disposed within said envelope space for feeding ventilation air from said supply duct into said envelope space. 
     
     
       4. An environment control system as claimed in  claim 3 , wherein each ventilation air branch line includes at least one nozzle for injecting ventilation air into the envelope space. 
     
     
       5. An environment control system as defined in  claim 4 , wherein at least one nozzle is a shell-side nozzle capable of injecting envelope space ventilation air between an insulation jacket disposed in said envelope space, and said body shell. 
     
     
       6. An environment control system as defined in  claim 5 , wherein two or more shell-side nozzles are provided in communication with each ventilation branch line, the shell-side nozzles being disposed at spaced intervals around a circumference of the envelope space. 
     
     
       7. An environment control system as defined in  claim 6 , wherein at least one nozzle is an interior space-side nozzle capable of injecting envelope ventilation air between an insulation jacket and the liner. 
     
     
       8. An environment control system as defined in  claim 7 , wherein two or more interior space-side nozzles are provided in communication with each ventilation branch line, the interior space-side nozzles being disposed at spaced intervals around the circumference of the envelope space. 
     
     
       9. An environment control system as defined in  claim 1 , wherein an anti-corrosion/volatile organic compound sorption treatment is applied to an interior surface of the aircraft structure possibly exposed to condensation. 
     
     
       10. An environment control system as defined in  claim 9 , wherein the anti-corrosion/volatile organic compound sorption treatment is formulated to provide acceptable characteristics of: 
       adhesion to metal surfaces;  
       hydrophobic;  
       low flammability; and  
       low off-gassing at typical envelope space temperatures during cruising flight.  
     
     
       11. An environment control system as defined in  claim 10 , wherein the anti-corrosion/volatile organic compound sorption treatment is formulated to: 
       resist solidification within the aircraft envelope space;  
       sorb ventilation air volatile organic compound at typical envelope space temperatures during cruising flight and desorb said ventilation air volatile organic compounds at warmer temperatures substantially without hysteresis.  
     
     
       12. An environment control system as defined in  claim 1 , wherein the return air control unit is adapted to draw the return air stream from the interior space only. 
     
     
       13. An environment control system as defined in  claim 12 , wherein the return air control unit comprises a housing, an envelope opening defined in the housing and in communication with the envelope, an interior space opening defined in the housing and in communication with the interior space, and a damper capable of selectively closing the envelope opening and the interior space opening. 
     
     
       14. An environment control system as defined in  claim 1 , wherein the liner has a leakage area such that the flow of air into the envelope space required to develope a pressure in said envelope space required to develope a pressure in the interior space is less than 10cfm per occupant seat. 
     
     
       15. An environment control system as defined in  claim 1 , further comprising air flow barriers disposed within the envelope space and which divide the envelope space into a plurality of envelope space sections, and ventilation means capable of supplying ventilation air from said distribution system to an envelope space section at a flow rate which is different from the flow rate of air to another envelope space section. 
     
     
       16. An environment control system as claime in  claim 15 , wherein said ventilation means includes ventilation to each envelope space section. 
     
     
       17. An environment control system as defined in  claim 16 , wherein a flow blocker is disposed within the envelope space at approximately mid-height of an upper lobe of the body of the aircraft. 
     
     
       18. An environment control system as defined in  claim 2 , wherein the interior space air distribution system comprises: 
       an air conditioner communicating with the air supply for receiving interior ventilation air for the interior space and operative to condition the interior space ventilation air to create supply air for the interior space; and  
       a supply air duct capable of directing the interior space supply air into the interior space.  
     
     
       19. An environment control system as defined in  claim 18 , wherein the air conditioner is operative to maintain a relative humidity of the cabin supply air of at least 20%. 
     
     
       20. An environment control system as defined in  claim 19 , wherein the air conditioner is operative to maintain a relative humidity of the cabin supply air of between 20% and 80%. 
     
     
       21. An environment control system as defined in  claim 20 , wherein the air conditioner is operative to maintain a relative humidity of the cabin supply air of between 40% and 70%. 
     
     
       22. An environment control system as defined in  claim 16 , wherein each envelope section has a respective duct for enabling air to be drawn therefrom, 
       and further including a controller for controlling the flow of air from an envelope space section independently of another envelope space section.  
     
     
       23. An environment control system as defined in  claim 15 , further comprising an insulation jacket disposed within said envelope space and wherein the ventilation means for at least one envelope space section includes a ventilation outlet port between said jacket and said shell. 
     
     
       24. An environment control system as defined in  claim 15 , further comprising an insulation jacket disposed in said envelope space, and wherein said envelope space for at least one envelope space section includes a ventilation outlet port disposed between said insulation jacket and said liner. 
     
     
       25. An environment control system as defined in  claim 1 , wherein said air supply is provided from an engine of said aircraft, and said control system comprises a first air conditioner for controlling the temperature of the air from said engine and for supplying said air to said envelope air distribution system, a second air conditioner for receiving air supplied from an engine of said aircraft and for conditioning the temperature of said air, and air feeding means for feeding the air from said second air conditioner into said interior space. 
     
     
       26. An environment control system as defined in  claim 1 , wherein the interior space includes at least one floor defining a cabin space above said floor, and said system further comprises flow barrier means, including a flow blocker, disposed in said envelope space at a level different than the level of the or each cabin space floor, and defining an upper envelope space above said flow blocker and a lower envelope space below said flow blocker, wherein said flow barrier means is arranged to substantially prevent air which resides in the upper and lower envelope spaces from flowing between said upper envelope space and said lower envelope space, through the space between said body shell and said liner, thereby to reduce stack pressure across said liner. 
     
     
       27. An environment control system as claimed in  claim 26 , wherein insulation is disposed in said envelope space, and said flow blocker is disposed between at least one of said liner and said insulation and said body shell and said insulation. 
     
     
       28. An environment control system as defined in  claim 27 , wherein the envelope air distribution system comprises at least one nozzle capable of injecting at least a portion of the envelope ventilation air steam into a portion of the envelope below said flow blocker, and at least one nozzle capable of injecting at least a portion of the envelope above said flow blocker. 
     
     
       29. The method of  claim 26 , further comprising the step of humidifying the interior space ventilation air prior air supplying the same to the interior space. 
     
     
       30. The method of  claim 26 , further comprising the steps of venting a portion of the return air stream out of the aircraft and recirculating a remaining portion of the return air stream back into the interior space. 
     
     
       31. A method as claimed in  claim 26 , wherein the surface of the body shell within the envelope space has an anti-corrosion/volatile organic compound sorption treatment applied thereto and the step of supplying envelope space ventilation air to the envelope space includes directing the ventilation air at the anti-corrosion/volatile organic compound treatment on the inside surface of said body shell. 
     
     
       32. A method as claimed in  claim 26 , wherein the step of supplying envelope space ventilation air to the envelope space comprises the step of passing said ventilation air through at least one nozzle. 
     
     
       33. A method of controlling the environment within an aircraft body having a body shell enclosing an inner space, a liner disposed within the inner space and defining an envelope space between the liner and the body shell and an interior space on the other side of the liner, the method comprising: 
       a) providing a flow of dry ventilation air;  
       b) dividing the flow of ventilation air into an envelope space ventilation air stream and an interior space ventilation air stream;  
       c) supplying the envelope space ventilation air to the envelope space;  
       d) supplying the interior space ventilation air to the interior space;  
       e) drawing a return air stream from the interior space; and  
       f) controlling the envelope space ventilation air stream and the interior space ventilation air stream to develop a sufficient pressure in the envelope space relative to the pressure in the interior space to substantially prevent the flow of air from the interior space into the envelope space caused by stack pressure across the liner between the envelope space and the interior space which tends to cause air to flow across the liner from the interior space into the envelope space.  
     
     
       34. The method of  claim 33 , further comprising the step of injecting at least a portion of the envelope ventilation air into a space between said body shell and an insulation jacket disposed between said liner and said body shell. 
     
     
       35. The method of  claim 33 , further comprising the step of injecting at least a portion of the envelope ventilation air into a space between an insulation jacket, disposed in said envelope space, and said liner. 
     
     
       36. The method of  claim 33 , further comprising the step of humidifying the interior space ventilation air prior to supplying the same to the interior space. 
     
     
       37. The method of  claim 33 , further comprising the steps of venting a portion of the return air stream out of the aircraft and recirculating a remaining portion of the return air stream back into the interior space. 
     
     
       38. A method as claimed in  claim 33 , wherein the surface of the body shell within the envelope space has an anti-corrosion/volatile organic compound sorption treatment applied thereto and the step of supplying envelope space ventilation air to the envelope space includes directing the ventilation air at the anti-corrosion/volatile organic compound treatment on the inside surface of said body shell. 
     
     
       39. A method as claimed in  claim 33 , wherein the step of supplying envelope space ventilation air to the envelope space comprises the step of passing said ventilation air through at least one nozzle. 
     
     
       40. A method as claimed in  claim 33 , further comprising the step of providing a flow blocker in the envelope space at a level other than the level of a floor of the interior space and defining an upper envelope space above said flow blocker and a lower envelope space below said flow blocker, wherein said flow blocker is arranged to sunstantially prevent air which resides in the upper and lower envelope spaces from flowing between said upper envelope space and said lower envelope space through the space between said body shell and said liner, thereby to reduce stack pressure across said liner. 
     
     
       41. An environment control system installed in the body of an aircraft, the aircraft having a body shell enclosing an inner space, a liner disposed within the inner space and defining an envelope space between the liner and the body shell, and an interior space on the other side of the liner, the interior space including at least one floor defining a cabin space above said floor, the environment control system comprising flow barrier means, including a flow blocker, disposed in said envelope space at a level different than the level of the or each cabin space floor and defining an upper enbelope space above said flow blocker and a lower envelope space below said flow blocker, wherein said flow barrier means is arranged to substantially prevent air which resides in the upper and lower envelope spaces from flowing between said upper envelope space and said lower envelope space through the space between said body shell and said liner, thereby to reduce stack pressure across said liner. 
     
     
       42. An environment control system as claimed in  claim 41 , comprising insulation disposed in said envelope space, and wherein said flow blocker is disposed between at least one of said liner and said insulation and said body shell and said insulation. 
     
     
       43. An environment control system as claimed in  claim 42 , wherein said flow blocker is arranged to compress said insulation towards said body shell. 
     
     
       44. An environment control system as claimed in  claim 41 , wherein said flow blocker is positioned at about mid-height of said envelope space above said floor level. 
     
     
       45. An environment control system as claimed in  claim 41 , comprising at least one said flow barrier means disposed within the envelope space on each side of said aircraft. 
     
     
       46. An enviroment control system as claimed in  claim 45 , comprising a plurality of said flow barrier means disposed within said envelope space on each side of said aircraft, and being spaced from one another about the circumference of said envelope space. 
     
     
       47. An environment control system as claimed in  claim 41 , further comprising an air supply for providing a flow of dry ventilation air to the inner space of the body, an envelope air distribution system for directing air from the air supply into the envelope space and wherein the envelope air distribution system includes at least one outlet port for injecting envelope ventilation air into said upper envelope ventilation air into the lower envelope space. 
     
     
       48. An environment control system installed in the body of an aircraft having a body shell enclosing an inner space, a linear disposed within the inner space and defining an envelope space between the linear body shell, and an interior space on the other side of the linear, 
       an air supply for providing a flow of dry ventilation air into the inner pace of the body,  
       air feeding means for feeding a flow of air from the air supply into the envelope space, and wherein the linear has a leaskage area such that the flow of air into the envelope space required to develope a pressure in the envelope space of at least 0.5Pa above the pressure in the interior space is less than 10cfm per occupant seat.  
     
     
       49. An environment control system as claimed in  claim 48 , wherein the interior space includes a cabin space for accomodating people and having a cabin space floor, the environment control system further comprising flow barrier means, including a flow blocker, disposed in said envelope space above the level of said cabin space floor and defining an upper envelope space above said flow blocker and a lower envelope space below said flow blocker, wherein said flow barrier means is arranged to substantially prevent air which resides in the upper and lower envelope spaces from flowing between said upper envelope space and said lower envelope space through the space between said body shell and said linear, thereby to reduce stack pressure across said linear. 
     
     
       50. An environment control system installed in the body of an aircraft, the aircraft having a body shell enclosing an inner space, a linear disposed within the inner space and defining an envelope space between the liner and body shell and an interior space on the other side of the liner, and insulation disposed within said envelope space, the control system comprising an air supply for providing a supply of air from an engine of said aircraft to the inner space of the body, an envelope air distribution system for directing air into the envelope space, said distribution system comprising at least one envelope supply duct for feeding air along said aircraft body and at least one ventilation air branch line disposed within said envelope space for feeding ventilation air from said supply duct into said envelope space between said linear and said insulation, a first air conditioner for controlling the temperature of the air from said engine and for supplying said air to said distribution system, a second air conditioner for receiving air supplied from an engine of said aircraft and for conditioning the temperature of said air, and air feeding means for feeding the air from said second air conditioner into said interior space. 
     
     
       51. An environment control system as claimed in  claim 50 , further comprising means for feeding air from said first air conditioner to said second air conditioner. 
     
     
       52. An environment control system as claimed in  claim 51 , comprising an air flow controller for controlling the flow of air from said first air conditioner to said second air conditioner. 
     
     
       53. An environment control system as claimed in  claim 50 , further comprising an air flow controller for controlling the flow of air from said first air conditioner to said air distribution system. 
     
     
       54. An environment control system as claimed in  claim 50 , further comprising a return air control unit capable of drawing return air from the interior space. 
     
     
       55. An environment control system as claimed in  claim 54 , further comprising a mixing unit for mixing air supplied from said engine and from said return air control unit, and supplying the mixed air to said interior space. 
     
     
       56. An environment control system as claimed in  claim 50 , further comprising a return air control unit capable of drawing air from said envelope space. 
     
     
       57. An environment control system as claimed in  claim 50 , further including air flow barriers disposed within the envelope space and which divide the envelope space into a plurality of envelope space sections, and ventilation means capable of supplying ventilation air from said distribution system to an envelope space section at a flow rate which is different from the flow rate of air to another envelope space section. 
     
     
       58. An environment control system as claimed in  claim 57 , including ventilation control means for independently controlling the ventillation to each envelope space section. 
     
     
       59. An environment control system as claimed in  claim 57 , further comprising an insulation jacket disposed within said envelope space, and wherein said ventilation system includes a ventilation outlet port for at least one envelope space section disposed between said insulation jacket and said shell. 
     
     
       60. An environment control system as claimed in  claim 57 , further comprising an insulation jacket disposed within said envelope space, and wherein said distribution system includes a ventilation outlet port for at least one envelope space section disposed between said insulation jacket and said liner. 
     
     
       61. An environment control system as claimed in  claim 50 , wherein the liner has a leakage area such that the flow of air into the envelope space required to develope a pressure in said envelope space of at least 0.5Pa above the pressure in the interior space is less than 10cfm per occupant seat. 
     
     
       62. An environment control system installed in the body of an aircraft, the aircraft having a body shell enclosing an inner space, a liner disposed within the inner space and defining an envelope space between the liner and the body shell, and an interior space on the other side of the liner, the control system comprising: 
       an envelope exhaust controller arranged for receiving gas directly from said envelope space and expelling said gas from said aircraft, and control means for controlling the pressure of gas in said inner space to maintain the pressure of said envelope space below that of said interior space.  
     
     
       63. An environment control system as claimed in  claim 62 , further comprising an air supply for providing a flow of air to the inner space of the body, means for directing a flow of ventilation air from said air supply into said interior space, and wherein said control means includes an air flow controller for controlling the flow of air into said interior space to maintain the pressure in the interior space above that of the envelope space. 
     
     
       64. An environment control system as claimed in  claim 62 , wherein said envelope exhaust controller includes a plurality of envelope exhaust ports spaced apart in a direction along the length of said envelope space. 
     
     
       65. An environment control system as claimed in  claim 64 , wherein said envelope exhaust controller further comprises a plurality of valves, each for controlling the flow ofn gas from a respective envelope exhaust port. 
     
     
       66. An environment control system as claimed in  claim 62 , further comprising air flow barriers disposed within the envelope space and which divide the envelope space into a plurality of envelope space sections, each section having an exhaust outlet port, and wherein said envelope exhaust controller is capable of controlling the flow of gas drawn from an envelope space section independently of another envelope space section. 
     
     
       67. An environment control system as claimed in  claim 62 , further comprising a fire suppression system for releasing a flow of fire suppressant into the envelope space. 
     
     
       68. An environment control system as claimed in  claim 67 , further comprising an air supply for providing a flow of dry ventilation air into the inner space, an envelope air distribution system for directing air from the air supply into the envelope space, and wherein the fire suppression system is connected to said envelope air distribution system for introducing fire suppressant into said distribution system. 
     
     
       69. An environment control system as claimed in  claim 68 , wherein said fire suppressant system comprises a container of fire suppressant and a valve operable to introduce fire suppressant from said container into said envelope air distribution system. 
     
     
       70. An environment control system as claimed in  claim 67 , wherein the first suppressant comprises any one or more of Halon, carbon dioxide, nitrogen, and other fire suppressant agents, or mixtures of these. 
     
     
       71. An environment control system as claimed in  claim 62 , wherein an anti-corrosion/volatile organic compound absorption treatment is applied to an interior surface of the aircraft structure possibly exposed to condensation. 
     
     
       72. An environment control system as claimed in  claim 71 , wherein the anti-corrosion/VOC sorption treatment is formulated to provide acceptable characteristics of: adhesion to metal surfaces; hydrophobic; low flammability; and low off-gassing at typical and below temperatures during cruising flight. 
     
     
       73. An environment control system as claimed in  claim 71 , wherein the anti-corrosion/VOC sorption treatment is formulated to: resist solidification within the aircraft envelope; sorb ventilation air VOCS at typical envelope temperatures during cruising flight and de-sorb said ventilation air VOCS at warmer temperatures substantially without hysterics. 
     
     
       74. The method of controlling the environment within an aircraft body, the body having a body shell enclosing an inner space, a liner disposed within the inner space and defining an envelope space between the liner and the body shell, and an interior space on the other side of the liner, an envelope exhaust duct for drawing gas directly from the envelope space and exhausting said gas from said aircraft, the method comprising the steps of: 
       drawing gas directly from said envelope space through said duct and exhausting the gas drawn through said duct directly from said aircraft, and controlling the pressure of gas in the liner space such that the pressure in the envelope space is below that of the interior space.  
     
     
       75. A method as claimed in  claim 74 , further comprising providing a flow of dry ventilation air into the interior space and controlling the pressure of air in said inner space such that the pressure of air in said interior space is greater than the pressure or air in said envelope space. 
     
     
       76. A method according to  claim 74 , further comprising supplying ventilation air to said envelope space. 
     
     
       77. A method according to  claim 74 , comprising performing the step of drawing gas from said envelope space when the aircraft is either on the ground, during the period of aircraft ascent to cruising altitude, or detecting smoke or fire in the envelope space and/or when injecting fire suppressant into the envelope space.